"Delulu" is a slang term derived from the word "delusional," primarily originating from the K-pop fan community around 2014. It is commonly used on social media to describe someone who holds unrealistic or overly idealistic beliefs or fantasies, especially about celebrities or influencers. For example, a fan who believes they will marry their favorite musician despite no real basis might be called "delulu"

. The term is often used humorously or playfully to highlight exaggerated fantasies or expectations, and it can also refer to someone being overly emotional or melodramatic in some contexts, such as on TikTok

. It generally implies that the person is out of touch with reality or has unrealistic expectations

. In summary, "delulu" means being delusional or disconnected from reality, especially in the context of fan culture and social media